The subject matter as disclosed herein relates to a transmission control protocol (TCP) relay apparatus for relaying TCP communication performed between communication devices that are connected to respective networks having different characteristics.
In recent years, cellular or mobile telecommunications systems are rapidly increasing year-by-year in the Internet-related traffic flowing therein. This results from advances in high-speed wireless communication technologies, such as radio communication networks compliant with the long term evolution (LTE) or like standards. In mobile communications systems, major characteristics of communications over wireless networks are such that these are broad in frequency band unlike wired networks and, on the other hand, are large in transfer delay, thereby posing a risk that instantaneous communication interruption occurs due to hand-over between base stations. It has been revealed that in networks of the type having such characteristics, various kinds of application programs using a default transmission control protocol/internet protocol (TCP/IP) suffer from performance deterioration, such as being unable to obtain sufficient throughputs.
Prior known performance improving schemes for suitably using the TCP in such network environments include a method for installing a TCP-terminating and relaying apparatus between a mobile phone and server and for performing default TCP transmission control between the relay apparatus and the server while performing, between the relay apparatus and the mobile phone, TCP transmission control optimized for wireless networks.
United States Patent Application Publication US 2011/0125915 A1 (referred to hereinafter as Literature 1) discloses therein a TCP transmission control device having a unit which sets up TCP transmission control information for use in a TCP connection to be established between a transmission-side terminal and its chosen reception-side terminal in compliance with the type of a network to which the reception terminal belongs. The TCP transmission control device disclosed in Literature 1 is specifically arranged to set up TCP transmission control information based on the kind of communication services and IP address routing information of the reception terminal.
By employing such an arrangement, the transmission-side device sets appropriate TCP transmission control information in accordance with a packet data communication network to which its associated opponent party's terminal belongs whereby it is possible to perform efficient TCP communication, thus making it possible to appreciably shorten a retransmission time in packet loss events. In addition, it becomes possible to set adequate TCP parameters in units of TCP connections with the use of existing architectures without having to modify the current TCP stack/protocols. By arranging the TCP relay apparatus to have its ability to perform the TCP transmission control method disclosed in Literature 1, it becomes possible to make the efficiency of TCP communications between a cell phone and server improved.